Madagascar has been experiencing a measles outbreak since early October 2018. The outbreak started in the urban health district of Antananarivo Renivohitra (in the heart of the capital city, Antanarivo) on 4 October 2018 when three measles cases were confirmed at the Pasteur Institute of Madagascar (IPM) by serology. The disease then spread to other health districts (Tanà South, Tanà North and Ambohidratrimo) in Analamanga Region (where the capital city is located) and subsequently to other parts of the country. The Ministry of Public Health formally declared the measles outbreak on 26 October 2018.